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The horizontal fraction bar was introduced by the Arabs.
People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Colchicine is a highly poisonous alkaloid originally extracted from a type of saffron plant that is used mainly to treat gout.